Electronic circuits are used in a wide variety of applications and products for many purposes, including communication, audio/video, security, general and special purpose computing, data compression, digital signal processing, and medical devices, to name a few. Current consumer trends focus on increasingly powerful devices with increased portability. It can prove challenging to achieve more processing power while simultaneously improving energy efficiency. Improved energy efficiency translates to longer battery life, which is an important factor in the design and use of portable electronic devices. To enable small form factor devices to have complex functionality along with efficiency in power consumption, designers often utilize a system-on-chip (SoC).
SoCs are constructed using a variety of modules and/or sub-systems used to perform specific functions. These are integrated together with a communication medium (such as a system bus). Each module can have different timing requirements. The integration of modules with varying clock and timing requirements can create challenges in the designing, testing, and verification of complex SoCs.
Timing is an important consideration in the design of a complex circuit or SoC. In practice, the arrival time of a signal can vary for many reasons. The various values on input data can cause different operations or calculations to be performed, introducing a delay in the arrival of a signal. Furthermore, operating conditions such as temperature can affect the speed at which circuits may perform. Variability in the manufacture of parts can also contribute to timing differences. Properties such as the threshold voltage of transistors, the width of metallization layers, and dopant concentrations are examples of parameters that can vary during the production of integrated circuits, potentially affecting timing.
A large-scale architecture with many subsystems can typically result in a large number and variety of interacting clock domains. Synchronizing all the clock domains can be rendered difficult by engineering costs, power consumption, and project-level risks. Accordingly, such architectures and designs increasingly utilize multiple asynchronous clock domains. The use of a variety of different domains can make timing analysis even more challenging.
Designers of SoCs and other integrated circuits often need to transfer data between multiple subsystems. This data may include asynchronous data such as control and configuration commands, isochronous data such as video packets that have strict temporal and jitter requirements, and/or other synchronous, periodic data. Some applications require high levels of data integrity and/or bandwidth. Systems and methods of data transfer between such entities are an invaluable part of modern logic circuit design. A thorough characterization of timing behavior across a variety of conditions is essential for a circuit designer. The timing between various sections or modules may need to be understood and verified across a range of operating conditions, as the timing can be important for functions such as data transfer. Timing analysis continues to be an invaluable part of modern logic circuit design.